1. Field of the Invention
The present invention relates generally to seeder machines capable of selectively delivering plant seeds from a reservoir thereof and delivering them into a seed germination tray, but more particularly to seeder machines of the needle variety that incorporate a plurality of vacuum assisted needles or cannula configured to take possession of a single seed or multiple seeds and depositing them into a germination tray to promote their germination and growth.
2. Description of the Related Art
It is well known that virtually all plants and flowers, other than those that are tubor propagated or grafted, begin their growth cycle with the sowing of a single seed. Considering the millions of plants and flowers sold in the wholesale and retail marketplace, and the length of the spring and summer growing seasons, in order to meet consumer market demands time management in the growing industry is considered critical by the growers.
In the past, virtually all seeds were placed manually by hand into the soil filled cells, cavities or compartments of germination trays or "flat". The germination flats are then watered and cared for to enable the seed to germinate into a small seedling having foliage only inches tall. When the seedling is only inches tall, it is known that it begins to become root bound within the germination tray and must be transplanted into a larger tray or cup-like container having a much greater volume than the cells of the germination flat in which the seeds were initially placed. Only within the past several years have machines been constructed to perform this transplanting function and they have greatly advanced the efficiency of the growing industry. One such machine, considered by many as the industry standard with respect to efficiency and versatility is the PLUGPLANTER automated transplanter manfactured by Bouldin & Lawson, Inc. of McMinnville, Tenn.
The advent of the automated seeding machine is believed to be another highly useful and efficient machine which has been well received by the planting ad growing industry. There are two principal types of automated seeding machine. They are: the drum seeder and the needle seeder. A drum seeder typically includes a rotating drum configured to roll over a germination flat and transfer a single seed from the surface of the drum into the cavities of the flat. The operable configuration of the drum is believed to be critical for effective seed deposition and may be varied depending upon the type and configuration of the flat being used.
A needle seeder typically includes a needle carrier of some type configured with a plurality of needles including a cannulated portion through which a vacuum or suction is established. The needle size, corresponding to the internal diameter of the canula, is user selected depending upon the type and configuration of the seed to be sown. Once the suction force is established at the tip or distal end of the canula, the needle assembly may be inserted into a quantity of seed at which time a single seed or several seeds become lodged against the opening in the cannula due to the force of the suction.
The needles are then typically moved to a sowing position at which time the suction is relieved or reversed to expel the seed(s) from the tip of the canula into the cavities of the germination tray. Prior to the present invention, automated needle seeders caused the percent yield of seedlings to increase. Coupled with better seed stock, the grower was able to achieve superior seedling yields in less time, and at a cost savings, as compared to manually sowing of seeds. However, the yield of seedlings was still not completely acceptable to some growers. Most often the yield of seedlings was attributable to open cells in the germination flat. That is, a cell that did not get a seed sown into it.
After considerable investigation by the record owners of the present invention, it was determined that at least two factors contributed to "open cell" conditions during the seed sowing operations using needle seeders. First, it was determined that the manner in which needle carrier, and thus the needles, moved to the sowing position entailed a non-linear movement. That is, the needle carrier traveled up and over an obstacle or step to a substantially horizontal position. This movement "over the hump" caused a slight jarring of the seed attracted to the cannula which often resulted in the seed becoming dislodged from the tip of the cannula causing it to fall off before it was released into the cell of the germination tray, thereby resulting in an open cell.
The second problem relates to the manner in which the other commercially available needle seeders handled seed dust which is inherent in all large bulk quantities of seed. The seed dust was found to have been readily mixed and inseparable from the seed stock allowing the dust to be sucked into the cannula and deposited into the germination tray instead of a seed, or the dust clogged the cannula preventing it from capturing a seed. Often times a clogged cannula is not discovered until several flats had been processed which resulted in numerous open cells.
Thus, in automated seeding operations a device which would be most desirable would minimize the possibility of open cell conditions. In this manner the grower maximizes his growing efficiency and yield of seedlings after they have germinated. With regard to the aforementioned problems, when a seed is dislodged from its cannula by the travel of the seed carrier assembly, an open cell or cavity is the result. Similarly, when seed dust clogs or takes the place of a seed, this too means an open cell in the germination flat. Open cells in germination flats result in wasted growing space to the grower and wasted material in the nature of soil mixtures filling their cells or cavities not having a seed for germination, and thus lower seedling yields and lost profits.
Accordingly, a needle type automated seeder constructed in such a manner as to separate seed dust from the seeds to be sown, and move its seed carrier assembly smoothly and without jarring or the seeds captured by the needle cannula would be an desired by the grower and user of such a machine.